Allan J. MacEachen, a driving force behind social policy changes under two prime ministers, has died at the age of the 96 after a lifetime saturated with politics and parliamentary manoeuvres.

MacEachen was one of Canada's most powerful cabinet ministers of the postwar era and held a variety of posts, including a term as minister of national health and welfare from 1965-1968 during the creation of medicare.

As labour minister, MacEachen was also instrumental in reforming the labour code and establishing a new standard for the minimum wage. His other portfolios also included finance and he twice served as secretary of state for external affairs.

Prime Minister Justin Trudeau, whose father, Pierre, relied heavily on MacEachen when he was prime minister, said Wednesday his cabinet had a moment of silence for "one of the very finest ministers ever to serve this country."

"I'm not going to list his many, many accomplishments but I do want to reflect on one," he said at the end of a three-day cabinet retreat in St. John's, N.L. "Universal public medicare is maybe our proudest achievement as a country. It was the dream of many of us for many years.

"In 1966, when Prime Minister (Lester B.) Pearson needed someone to actually make it happen, to design the legislation to make it happen and to get it through a minority parliament, he turned to Allan J.," Trudeau said. "For that and for so many other things Canada is a better country because he was in it and he served it."

In his memoirs, Pierre Trudeau recalled the Cape Bretoner as a intensely private person who had a finely tuned sense of political strategy.

"He lived and breathed politics," wrote the former Liberal leader, who was photographed on several occasions leaning over and whispering confidences to his trusted colleague.

Former prime minister Jean Chretien described his former cabinet colleague as "one of the greatest political figures I've met in my long political career. ... In his life in the House of Commons, he was very skilled."

Liberals who spent brief tenures in MacEachen's office through the decades, or enjoyed his political support later in life, describe a man of contrasts.

He could be a brilliant baritone speechmaker in the House of Commons one day, and the next could fall into periods of such prolonged silence that a press secretary meeting with him once asked, "Sir, have you left the room?"

He was a politician comfortable on the international stage, battling for issues such as an extension of Canada's offshore fishing boundaries, yet was equally fond of telephoning friends in Inverness County, Cape Breton, for advice -- or spending a morning battling for a rejected unemployment insurance claim.

Frank McKenna, one of many assistants who MacEachen mentored, said each political pupil was taught to believe in the value of government and the possibilities of creating a "public good" in the longer term.

"It was a mind-blowing experience for me watching a modest man from a challenged region ... become one of the country's leading voices. It was an inspiration to what is possible," said McKenna, a former premier of New Brunswick.

Bob Rae, a friend and former Liberal MP, said in an interview that MacEachen -- who spoke fluent Gaelic -- always remembered he was the son of a Cape Breton coal miner, and he was ultimately dedicated to creating lasting legislation that led to social improvements.

"He was the architect of the major social policy changes that took place in Canada in the mid 1960s," said Rae, who once faced MacEachen as an NDP critic and later gained his support in his 2006 bid for leadership of the Liberal party.

Rae described MacEachen as both a left-leaning Liberal who was influenced by the co-operative movement founded by Rev. Moses Coady in Antigonish, N.S., and a pragmatist who aimed to make theory into reality.

It was largely MacEachen's skill as a parliamentarian that helped defeat then-Tory prime minister Joe Clark in a non-confidence motion brought by Rae in 1979.

"He was instrumental in the coming back of Trudeau," recalled Chretien in an interview.

Some of his legislation didn't work out as well, particularly a post-1980 budget.

Trudeau's memoirs recall MacEachen's efforts as finance minister to bring in tax reform that closed a number of loopholes, and the resulting opposition.

"The outcry was such that MacEachen was forced to withdraw many of his measures," wrote the former prime minister.

Chretien said that MacEachen survived setbacks with good humour, and in their frequent voyages together to Cape Breton he came to see a man beloved among his own people.

"We were talking politics like hockey players must talk about hockey. ... Politics can be a lot of fun," said the former prime minister.

The many politicians taught by MacEachen came to be part of his extended network, said John Young, a former leader of the Liberal Party in Nova Scotia who was his assistant in the early 1970s.

"He would sit you down and tell you, 'Government has a purpose in society and that is to serve the public good,"' he recalled.

Born in Inverness on Cape Breton Island in 1921, MacEachen was first elected in 1953 in the Inverness-Richmond riding under Liberal prime minister Louis St. Laurent.

MacEachen won again in 1957, but lost his seat in 1958 before winning eight more elections, including the last five while representing Cape Breton-Highlands Canso.

He also served as deputy prime minister and was appointed to the Senate in 1984, where he remained until 1996.

MacEachen, who ran an unsuccessful campaign for the Liberal leadership in 1968, was named an Officer of the Order of Canada in 2008.

Young said that MacEachen was always acutely aware of the ordinary electors who put him in Parliament, and he spent his final years at his residence in Lake Ainslie, in Inverness County, and Antigonish, N.S.

"He'd say, 'I don't care how important you think you are in Ottawa. If your constituents don't think you're important to them, you won't be here."'